Patch matrix arrived / Jomox polysynth / Front panel designer

Haible Juergen Juergen.Haible at
Tue Mar 17 13:02:28 CET 1998


I'm back from my short holidays, and here are some news:


more VCS3 modules are finished, and I just received the patchmatrix
I've ordered from Ghielmetti in Switzerland. (
I bought a 20 x 20 matrix
which is slightly larger than the EMS one, but this is currently in
production, and I got it one week after I've ordered it.
It is of *awsome* quality (nothing like the cheap 10 x 10 I had bought
from Farnell, and which is also made by Gielmetti). The Pins are really
sturdy - something I expect to last some time. In retrospect, I am very
happy that I have abandoned the idea of a matrix from discrete jacks,
or stackable 2mm plugs or what else.
I've also bought 30 pins. These are *not* compatible to the EMS pins.
The handle is very similar, but the contact area has a larger diameter.
They have diodes inside, and I am currently replacing these with 2k7
resistors. I destroyed the first two pins, and then I found a workable
way to
open them. Fix the contact area tightly between the wooden parts of the
"workmate", then use one half of a wooden clothespin as a lever to
the plastic cap. Inside the diodes are soldered to the pin in a very
way, without excess lead that would cause trouble when the cap is put 
into place. So I decided to use these perfect solder joints as well, and
cut out
the diode directly at its body, leaving its wires at the pin. Then I
soldered a small
resistor directly to the diode's wires ant put on the cap again.
Works perfect after the 2nd or 3rd pin.

Now it's time to design a front panel, and build the remaining few

Anybody knows what reverb tank is inside the VCS3 ? (length, number of
input and output impedance, manufacturer code ... ?)

I was in Frankfurt last week (sorry that I couldn't meet all the people
I wanted to),
and one of the most interesting things I saw (besides the new MAM stuff,
of course),
was this polyphonic Jomox synth. No, I couldn't hear it - the only thing
they showed
were the voice cards: complete analogue voices built from standard SMD
VCO is build around a transistor array (don't know which one), with two
resistors glued on top of it (They looked like plastic transistors, but
I asked and
the guy confirmed it were tempco resistors). The filter is built from
four 3080-stages.

The Yamaha EX-5 has the nice E-Piano sounds I was looking for (try a
called "Suitcase 73" !), but a crappy keyboard action. The expander
version may be 
interesting when it is dropped in price in a few years.

I didn't play any of the new virtual analogue stuff. Too many computer
in Hall 9 for my taste, this year.

I found a manufacturer for front panels in single or small quantities in
They offer a free frontpanel design tool for download on their homepage.
You draw your frontpanel with this tool, and it will directly provide
the right input data
for their CNC machine. Great idea ! To make it even better, the program
the price after each edit operation you do. Add another 10mm diameter
hole, see
the price increase by DM 0.34 . Why doesn't anybody else do it like this
I think I'll give them a try with the EMS clone frontpanel.


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